Updating families without losing instance parameters

[mark.mcmullan]

Hello,

When I started into my MEP design, I placed some fairly generic supply air grilles, and gave them each the correct Flow (Instance Parameter) required. Now i want to replace those generic grilles with something a little more realistic. The new family has a flow instance parameter too. How do i update them all at once, without resetting the flow on them all, and resetting the system they are assigned to?

Also, I have a pressure drop instance parameter. Is it possible to go into a schedule, and edit each pressure drop value manually, rather than do it in a plan view?

Thanks in advance

Mark

[cporter.207875]

Hello,

When I started into my MEP design, I placed some fairly generic supply air grilles, and gave them each the correct Flow (Instance Parameter) required. Now i want to replace those generic grilles with something a little more realistic. The new family has a flow instance parameter too. How do i update them all at once, without resetting the flow on them all, and resetting the system they are assigned to?

Also, I have a pressure drop instance parameter. Is it possible to go into a schedule, and edit each pressure drop value manually, rather than do it in a plan view?

Thanks in advance

Mark

You ought to be able to set the parameter values directly from the schedule. We do this for most of our equipment and fixtures.
Unfortunately, you may be out of luck on the instance parameter issue. We've had the same problem in our office.

Post back if you find a way to keep the flow value when you substitute for another terminal.

[jbaumann]

Hello,

When I started into my MEP design, I placed some fairly generic supply air grilles, and gave them each the correct Flow (Instance Parameter) required. Now i want to replace those generic grilles with something a little more realistic. The new family has a flow instance parameter too. How do i update them all at once, without resetting the flow on them all, and resetting the system they are assigned to?

Also, I have a pressure drop instance parameter. Is it possible to go into a schedule, and edit each pressure drop value manually, rather than do it in a plan view?

Thanks in advance

Mark

For family parameters (not shared parameters) when updating / overwriting a family in Revit MEP the instance parameters should not lose their current values unless you replaced or renamed the parameter. For example if you renamed the "Flow" instance parameter to "Airflow", Revit will overwrite the instance parameters with the default value for that family and type.

However, even if you create from scratch a new Air Terminal family and add family instance parameters with identical names to your current family in the project, Revit will retain the values you had set in the project.

Shared parameters act differently because Revit assigns each shared parm a GUID (globally unique identification) number.

If your "pressure drop" parameter is a shared parameter you will be able to add it to a schedule and update the values in the schedule rather than plan view.

[psyclone69]

...should not lose their current values unless you replaced or renamed the parameter.

Thanks for this! While creating a new instance parameter I also "updated" all my existing instance parameter names... I couldn't understand why all the instance parameters were lost!